The facts: More and more people are changing to a gluten-free diet in the hope that it will make them healthier. According to consumer analyst group Datamonitor, the worldwide market for gluten-free foods is expected to be worth about US$4.3 billion by 2015 - that's 40 per cent more than in 2010. Unfortunately, for many of us gluten-free foods are nothing more than a waste of money.

Gluten is a protein found in wheat, barley and rye. According to Charmain Tan, registered dietitian from Seventeen Nutrition Consultants, and the American Overseas Dietetic Association country representative for Hong Kong, foods that don't contain gluten are used as a treatment for an autoimmune disorder called coeliac disease.

In people with the condition, the body mistakes dietary gluten for a harmful substance and reacts to it by producing antibodies to fight it. This immune reaction can cause inflammation and damage to the lining of the small intestine.

Common symptoms of coeliac disease include gastrointestinal discomfort like cramping, constipation and diarrhoea, as well as fatigue, bone and joint pain and rashes.

Gluten-free foods are also recommended for those who suffer from non-coeliac gluten sensitivity. By consuming these foods, gluten-intolerant people are able to get a handle on their symptoms.

Many consumers are under the impression that gluten-free foods are low in carbohydrate and may help them lose weight, but Tan says that this is wrong. In fact, there are many gluten-free foods out there that aren't derived from wheat, rye or barley that do contain carbohydrate. These include rice, corn, polenta, tapioca and many fruits.

Therefore, if you do not suffer from coeliac disease or gluten intolerance, there's really no need to switch to a gluten-free diet.

"Sticking only to gluten-free foods can be quite restrictive. If you want to adopt a gluten-free diet, it's best to consult your health care professional for advice and a diagnosis of coeliac disease or gluten intolerance first," Tan says.

"Gluten-free products offer no specific advantages to healthy folks, plus they are about two or three times more expensive than a similar product that contains gluten."